Study on Factors Degrading the Accuracy of Real Beam Modal Decomposition

Three factors that degrade the accuracy of modal decomposition are extensively studied using simulated and measured beams. These include a beam size mismatch, beam center mismatch, and signal-to-noise ratio of the images. The beam size and beam center are scanned using simulated noisy beams, and the result of the modal decomposition is compared with that of real beams. Based on the suggested procedure, error functions of approximately 1-4 × 10-3 can be acquired for real beams. This study provides important information regarding the impact of the three factors on the practical modal decomposition and tolerances of a mismatch, helping estimate the achievable values of the error function in a real beam modal decomposition.